TRACHEATA 379 



The pupae lie in a cocoon which is found in the neighbour- 

 hood of their food plant, often on the ground. Athalia spinarum 

 is the turnip saw-fly ; and Lophyrus pini causes much damage 

 to young Scotch firs. 



Sub-order 2. Entomophaga. 



Chaeaoteeistics. — The abdomen is pedwnculated. A well de- 

 veloped ovipositor is present in the female. The larvae are 

 usually parasitic, in the larvae of other insects, sometimes in 

 plants ; they are apodal and aproctous. 

 Family Cynipidae (Gall-flies). — Small Hymenoptera with 

 a much-compressed abdomen, the first and second segments of 

 which are large, the others very short. There is a long coiled 

 ovipositor which arises near the base of the abdomen, and is 

 only fully extended when in use. The ova are large, and are 

 said to increase in size during developement. The larvae are 

 short white fleshy apodal grubs, which feed on the galls in 

 which they live. The pupae may be in the gall or under 

 ground. Some are parasitic in Diptera and Aphides. 



The oak-apple is formed by a member of this family, 

 Andricus terviinalis ; the common spherical woody galls in 

 the oak, by Cynips hollari ; and the " spangle galls " in the 

 leaves of the same tree by Neuroterus lenticidaris. Bhodites 

 rosae, another member of this family, gives rise to the beauti- 

 ful moss or bedeguar galls on rose-trees. 



Family Ichneumonidae (Ichneumons). — Insects with long 



Fig. 213. 

 Aphideus avenue, to the 



left. 

 Epliedrus plagiator, to the 



right. 



slender bodies, with an exserted, often very long ovipositor. 

 The abdomen has seven segments. The antennae are 



